MySQL语句之show
1 简介
SHOW有多种形式,可以提供有关数据库、表、列或服务器状态的信息。
2 创建测试数据
create table show_table( c1 int not null auto_increment, c2 varchar(10), c3 int(10), primary key(c1)
)engine=innodb;
insert into show_table values('', 'name1', 001);
insert into show_table values('', 'name2', 002);
insert into show_table values('', 'name3', 003);
insert into show_table values('', 'name4', 004);
insert into show_table values('', 'name5', 005);create table show_table_sec( c1 int not null auto_increment, c2 varchar(10), c3 int(10), primary key(c1)
)engine=innodb;
3 详细验证
3.1 SHOW AUTHORS 语句
作用:
显示mysql项目组人员信息。
基本语法:
SHOW AUTHORS
实例:
SHOW AUTHORS;
3.2 SHOW BINARY LOGS 语句
作用:
列出数据库服务器的二进制信息。
基本语法:
SHOW BINARY LOGS
SHOW MASTER LOGS
实例:
mysql> SHOW BINARY LOGS;
mysql> SHOW MASTER LOGS;
+------------------+-----------+
| Log_name | File_size |
+------------------+-----------+
| mysql-bin.000001 | 27338 |
| mysql-bin.000002 | 1035309 |
| mysql-bin.000003 | 126 |
| mysql-bin.000004 | 126 |
+------------------+-----------+
3.3 SHOW BINLOG EVENTS 语句
作用:
显示binlog日志信息,如果没有指定日志名称,则显示第一个二进制日志的信息。
基本语法:
SHOW BINLOG EVENTS[IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count]
实例:
mysql> show binlog events;
mysql> show binlog events in 'mysql-bin.000002';
mysql> show binlog events in 'mysql-bin.000002' from 107;
mysql> show binlog events in 'mysql-bin.000002' from 107 limit 3;
mysql> show binlog events in 'mysql-bin.000002' from 107 limit 2,3;
注:‘from 107 limit 3’ 从107开始取出3个事件。
‘from 107 limit 2,3’从107开始,偏移两个事件后取出3个事件。
3.4 SHOW CHARACTER SET 语句
作用:
SHOW CHARACTER SET语句用于显示所有可用的字符集,LIKE子句指示哪些字符集名称可以匹配,where子句列出所选字符集的信息。
基本语法:
SHOW CHARACTER SET[LIKE 'pattern' | WHERE expr]
实例:
show character set;
show character set like 'utf%';
show character set where charset = 'utf8';
注:Maxlen列显示用于存储一个字符的最大的字节数目。
3.5 SHOW COLLATION 语句
作用:
SHOW COLLATION SET语句用于显示所有可用的字符集校对,LIKE子句指示哪些字符集校对名称可以匹配,where子句列出所选字符集校对的信息。
基本语法:
SHOW COLLATION[LIKE 'pattern' | WHERE expr]
实例:
show collation;
show collation like 'utf8%';
show collation where Collation='utf8_bin';
注:Default列指示对于其字符集,整序值是否是默认值。Compiled指示字符集是否被编辑到服务器中。Sortlen与对字符串(在字符集中表达)分类所需的存储器的数量有关。
3.6 SHOW COLUMNS 语句
作用:
SHOW COLUMNS显示在一个给定表中的各列的信息。对于试图,本语句也起作用,FULL关键词会使得输出中包含您拥有的权限,并包含对每一列各自的评注。可以使用db_name.tbl_name作为tbl_name FROM db_name语法的另一种形式。
SHOW FIELDS是SHOW COLUMNS的同义词
基本语法:
SHOW [FULL] COLUMNS {FROM | IN} tbl_name [{FROM | IN} db_name][LIKE 'pattern' | WHERE expr]
实例:
show columns in show_table ;
show columns from show_table;
show columns from show_table from test;
show full columns from show_table from test;
show full columns from show_table from test like 'c%';
show full columns from show_table from test where field like 'c%';
3.7 SHOW CONTRIBUTORS 语句
作用:
显示mysql源码的贡献者。
基本语法:
SHOW CONTRIBUTORS
实例:
mysql> SHOW CONTRIBUTORS;
+-------------------+---------------------+-------------------------------------+
| Name | Location | Comment |
+-------------------+---------------------+-------------------------------------+
| Ronald Bradford | Brisbane, Australia | EFF contribution for UC2006 Auction |
| Sheeri Kritzer | Boston, Mass. USA | EFF contribution for UC2006 Auction |
| Mark Shuttleworth | London, UK. | EFF contribution for UC2006 Auction |
+-------------------+---------------------+-------------------------------------+
3.8 SHOW CREATE DATABASE 语句
作用:
显示用于创建给定数据库CREATE DATABASE语句。也可以使用SHOW CREATE SCHEMA。
基本语法:
SHOW CREATE {DATABASE | SCHEMA} [IF NOT EXISTS] db_name
实例:
show create database test;
show create schema test;
show create database if not exists test;
3.9 SHOW CREATE EVENT 语句
作用:显示创建事件(event)的信息
基本语法:
SHOW CREATE EVENT event_name
实例:
mysql> SET GLOBAL event_scheduler = ON;
mysql> drop event if exists show_event;mysql> CREATE EVENT test.show_event
ON SCHEDULE
every 1 HOUR
DO
insert into show_table values('', 'name6', 006);mysql> show create event show_event \G
3.10 SHOW CREATE FUNCTION 语句
作用:显示创建函数的信息
基本语法:
SHOW CREATE FUNCTION func_name
实例:参考SHOW CREATE PROCEDURE
3.11 SHOW CREATE PROCEDURE 语句
作用:显示创建存储过程的信息
基本语法:
SHOW CREATE PROCEDURE proc_name
实例:
mysql> DROP PROCEDURE IF EXISTS test.show_procedure;mysql> delimiter //
create procedure test.show_procedure()
begin insert into show_table values('', 'name7', 007);
end
//
delimiter ; mysql> call test.show_procedure();
mysql> SHOW CREATE PROCEDURE test.show_procedure() \G
3.12 SHOW CREATE TABLE 语句
作用:
显示用于创建给定表的CREATE TABLE语句。本语句对视图(trigger)也起作用。
基本语法:
SHOW CREATE TABLE tbl_name
实例:
mysql> SHOW CREATE TABLE show_table \G
*************************** 1. row ***************************Table: show_table
Create Table: CREATE TABLE `show_table` (`c1` int(11) NOT NULL AUTO_INCREMENT,`c2` varchar(10) DEFAULT NULL,`c3` int(10) DEFAULT NULL,PRIMARY KEY (`c1`)
) ENGINE=InnoDB AUTO_INCREMENT=29 DEFAULT CHARSET=latin1
3.13 SHOW CREATE TRIGGER 语句
作用:显示触发器的创建信息
基本语法:
SHOW CREATE TRIGGER trigger_name
实例:
mysql> drop trigger if exists show_trigger;mysql> delimiter //
create trigger show_trigger
after insert on show_table
for each row
begin insert into show_table_sec(c1, c2, c3) values(new.c1, new.c2, new.c3);
end//
delimiter ;mysql> show create trigger show_trigger \G
注:创建一个触发器show_trigger,当表show_table 有数据插入时,插入数据会同步插入到表show_table_sec。
3.14 SHOW CREATE VIEW 语句
作用:显示视图的创建信息。
基本语法:
SHOW CREATE VIEW view_name
实例:
mysql> drop view if exists show_view;
mysql> CREATE VIEW show_view AS SELECT c2, c3 from show_table where c1 < 5;
mysql> show create view show_view;
3.15 SHOW DATABASES 语句
作用:
SHOW DATABASES可以在MySQL服务器主机上列举数据库。也可以使用mysqlshow命令得到此清单。您只能看到您拥有某些权限的数据库,除非您拥有全局SHOW DATABASES权限。
与SHOW SCHEMAS作用及用法相同。
基本语法:
SHOW {DATABASES | SCHEMAS}[LIKE 'pattern' | WHERE expr]
实例:
mysql> show databases;
mysql> show schemas;
mysql> show databases like 'te%';
[root@localhost ~]# /usr/local/mysql/bin/mysqlshow
+--------------------+
| Databases |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| test |
+--------------------+
3.16 SHOW ENGINE 语句
作用:
SHOW ENGINE显示存储引擎的日志或状态信息.
基本语法:
SHOW ENGINE engine_name {STATUS | MUTEX}
实例:
mysql> show engine innodb status \G
mysql> show engine innodb mutex;
+--------+----------------+-------------+
| Type | Name | Status |
+--------+----------------+-------------+
| InnoDB | log0log.c:771 | os_waits=1 |
| InnoDB | buf0buf.c:1159 | os_waits=1 |
| InnoDB | log0log.c:832 | os_waits=24 |
+--------+----------------+-------------+
3.17 SHOW ENGINES 语句
作用:
SHOW ENGINES显示存储引擎的状态信息。对于检查一个存储引擎是否被支持,或者对于查看默认引擎是什么,本语句十分有用。
基本语法:
SHOW [STORAGE] ENGINES
实例:
mysql> show engines;
mysql> show storage engines;
注:Support值指示某个存储引擎是否被支持,并指示哪个是默认引擎。例如,如果服务器以--default-tabletype=InnoDB选项为起始,则InnoDB行的Support值为DEFAULT值。
3.18 SHOW ERRORS 语句
作用:
本语句与SHOW WARNINGS接近,不过该语句只显示错误,不同时显示错误、警告和注意。
LIMIT子句与SELECT语句具有相同的语法,请参见13.2.7节,“SELECT语法”。
SHOW COUNT(*) ERRORS语句显示错误的数目。您也可以从error_count变量中找回此数目:
SHOW COUNT(*) ERRORS;
SELECT @@error_count;
基本语法:
SHOW ERRORS [LIMIT [offset,] row_count]
SHOW COUNT(*) ERRORS
实例:
mysql> show errors;
mysql> show errors limit 2;
mysql> show errors limit 1,2;
mysql> show count(*) errors;
3.19 SHOW EVENTS 语句
作用:显示已创建的事件信息。
基本语法:
SHOW EVENTS [{FROM | IN} schema_name][LIKE 'pattern' | WHERE expr]
实例:
show events;
show events in test;
show events from test;
show events from test like 'show%';
show events from test where db ='test';
show events from test where definer like 'root@%' \G
3.20 SHOW FUNCTION CODE 语句
作用:需要mysql在编译时开启debug模式才能工作。
基本语法:
SHOW FUNCTION CODE func_name
实例:同下面3.28
3.21 SHOW FUNCTION STATUS 语句
作用:需要mysql在编译时开启debug模式才能工作。
基本语法:同下面3.29
SHOW FUNCTION STATUS[LIKE 'pattern' | WHERE expr]
实例:
3.22 SHOW GRANTS 语句
作用:
本语句列出了在为MySQL用户账户复制权限时必须发布的GRANT语句。
基本语法:
SHOW GRANTS [FOR user]
实例:
mysql> show grants;
mysql> show grants for current_user;
mysql> show grants for current_user();
mysql> show grants for root@localhost;
+---------------------------------------------------------------------+
| Grants for root@localhost |
+---------------------------------------------------------------------+
| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' WITH GRANT OPTION |
| GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION |
+---------------------------------------------------------------------+
3.23 SHOW INDEX 语句
作用:
SHOW INDEX会返回表索引信息。SHOW KEYS,SHOW INDEXES是SHOW INDEX的同义词。也可以使用mysqlshow -k db_name tbl_name命令列举一个表的索引。
基本语法:
SHOW {INDEX | INDEXES | KEYS}{FROM | IN} tbl_name[{FROM | IN} db_name][WHERE expr]
实例:
show index from show_table;
show indexes from show_table;
show keys from show_table;show index in show_table;
show index from show_table in test;
show index from test.show_table;
show index from show_table in test where Index_type like 'btree%';
3.24 SHOW MASTER STATUS 语句
作用:显示master主机二进制日志信息。
基本语法:
SHOW MASTER STATUS
实例:
mysql> show master status;
+------------------+----------+--------------+------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+------------------+----------+--------------+------------------+
| mysql-bin.000012 | 14412 | | |
+------------------+----------+--------------+------------------+
3.25 SHOW OPEN TABLES 语句
作用:显示打开的表
基本语法:
SHOW OPEN TABLES [{FROM | IN} db_name][LIKE 'pattern' | WHERE expr]
实例:
mysql> show open tables;
mysql> show open tables from test;
mysql> show open tables in test;
mysql> show open tables from test like 'show%';
mysql> show open tables from test where in_use < 4;
mysql> show open tables from test where name_locked < 4;
+----------+----------------+--------+-------------+
| Database | Table | In_use | Name_locked |
+----------+----------------+--------+-------------+
| test | show_table_sec | 0 | 0 |
| test | show_table | 0 | 0 |
| test | show_view | 0 | 0 |
+----------+----------------+--------+-------------+
3.26 SHOW PLUGINS 语句
作用:显示数据库存储引擎信息
基本语法:
SHOW PLUGINS
实例:
mysql> select * from information_schema.plugins;
mysql> show plugins;
+--------------------------+----------+--------------------+---------+-------------+
| Name | Status | Type | Library | License |
+--------------------------+----------+--------------------+---------+-------------+
| binlog | ACTIVE | STORAGE ENGINE | NULL | PROPRIETARY |
| mysql_native_password | ACTIVE | AUTHENTICATION | NULL | PROPRIETARY |
| mysql_old_password | ACTIVE | AUTHENTICATION | NULL | PROPRIETARY |
| MEMORY | ACTIVE | STORAGE ENGINE | NULL | PROPRIETARY |
| MyISAM | ACTIVE | STORAGE ENGINE | NULL | PROPRIETARY |
| CSV | ACTIVE | STORAGE ENGINE | NULL | PROPRIETARY |
| MRG_MYISAM | ACTIVE | STORAGE ENGINE | NULL | PROPRIETARY |
| InnoDB | ACTIVE | STORAGE ENGINE | NULL | PROPRIETARY |
| INNODB_TRX | ACTIVE | INFORMATION SCHEMA | NULL | PROPRIETARY |
| INNODB_LOCKS | ACTIVE | INFORMATION SCHEMA | NULL | PROPRIETARY |
| INNODB_LOCK_WAITS | ACTIVE | INFORMATION SCHEMA | NULL | PROPRIETARY |
| INNODB_CMP | ACTIVE | INFORMATION SCHEMA | NULL | PROPRIETARY |
| INNODB_CMP_RESET | ACTIVE | INFORMATION SCHEMA | NULL | PROPRIETARY |
| INNODB_CMPMEM | ACTIVE | INFORMATION SCHEMA | NULL | PROPRIETARY |
| INNODB_CMPMEM_RESET | ACTIVE | INFORMATION SCHEMA | NULL | PROPRIETARY |
| INNODB_BUFFER_PAGE | ACTIVE | INFORMATION SCHEMA | NULL | PROPRIETARY |
| INNODB_BUFFER_PAGE_LRU | ACTIVE | INFORMATION SCHEMA | NULL | PROPRIETARY |
| INNODB_BUFFER_POOL_STATS | ACTIVE | INFORMATION SCHEMA | NULL | PROPRIETARY |
| PERFORMANCE_SCHEMA | ACTIVE | STORAGE ENGINE | NULL | PROPRIETARY |
| FEDERATED | DISABLED | STORAGE ENGINE | NULL | PROPRIETARY |
| BLACKHOLE | ACTIVE | STORAGE ENGINE | NULL | PROPRIETARY |
| ARCHIVE | ACTIVE | STORAGE ENGINE | NULL | PROPRIETARY |
| partition | ACTIVE | STORAGE ENGINE | NULL | PROPRIETARY |
+--------------------------+----------+--------------------+---------+-------------+
3.27 SHOW PRIVILEGES 语句
作用:显示当前mysql服务器所支持的权限
基本语法:
SHOW PRIVILEGES
实例:
mysql> show privileges;
+-------------------------+---------------------------------------+-------------------------------------------------------+
| Privilege | Context | Comment |
+-------------------------+---------------------------------------+-------------------------------------------------------+
| Alter | Tables | To alter the table |
| Alter routine | Functions,Procedures | To alter or drop stored functions/procedures |
| Create | Databases,Tables,Indexes | To create new databases and tables |
| Create routine | Databases | To use CREATE FUNCTION/PROCEDURE |
| Create temporary tables | Databases | To use CREATE TEMPORARY TABLE |
| Create view | Tables | To create new views |
| Create user | Server Admin | To create new users |
| Delete | Tables | To delete existing rows |
| Drop | Databases,Tables | To drop databases, tables, and views |
| Event | Server Admin | To create, alter, drop and execute events |
| Execute | Functions,Procedures | To execute stored routines |
| File | File access on server | To read and write files on the server |
| Grant option | Databases,Tables,Functions,Procedures | To give to other users those privileges you possess |
| Index | Tables | To create or drop indexes |
| Insert | Tables | To insert data into tables |
| Lock tables | Databases | To use LOCK TABLES (together with SELECT privilege) |
| Process | Server Admin | To view the plain text of currently executing queries |
| Proxy | Server Admin | To make proxy user possible |
| References | Databases,Tables | To have references on tables |
| Reload | Server Admin | To reload or refresh tables, logs and privileges |
| Replication client | Server Admin | To ask where the slave or master servers are |
| Replication slave | Server Admin | To read binary log events from the master |
| Select | Tables | To retrieve rows from table |
| Show databases | Server Admin | To see all databases with SHOW DATABASES |
| Show view | Tables | To see views with SHOW CREATE VIEW |
| Shutdown | Server Admin | To shut down the server |
| Super | Server Admin | To use KILL thread, SET GLOBAL, CHANGE MASTER, etc. |
| Trigger | Tables | To use triggers |
| Create tablespace | Server Admin | To create/alter/drop tablespaces |
| Update | Tables | To update existing rows |
| Usage | Server Admin | No privileges - allow connect only |
+-------------------------+---------------------------------------+-------------------------------------------------------+
3.28 SHOW PROCEDURE CODE 语句
作用:需要mysql在编译时开启debug模式才能工作。
基本语法:
SHOW PROCEDURE CODE proc_name
实例:
3.29 SHOW PROCEDURE STATUS 语句
作用:需要mysql在编译时开启debug模式才能工作。
基本语法:
SHOW PROCEDURE STATUS[LIKE 'pattern' | WHERE expr]
实例:
3.30 SHOW PROCESSLIST 语句
作用:SHOW PROCESSLIST显示哪些线程正在运行。您也可以使用mysqladmin processlist语句得到此信息。如果有SUPER权限,可以看到所有线程。
基本语法:
SHOW [FULL] PROCESSLIST
实例:
mysql> show processlist;
mysql> show full processlist;
也可使用:bin/mysqladmin processlist -i 2
3.31 SHOW PROFILE 语句
作用:
show profile是由Jeremy Cole捐献给MySQL社区版本的。默认的是关闭的,但是会话级别可以开启这个功能。开启它可以让MySQL收集在执行语句的时候所使用的资源。为了统计报表,把profiling设为1。
基本语法:
SHOW PROFILE [type [, type] ... ][FOR QUERY n][LIMIT row_count [OFFSET offset]]type:ALL| BLOCK IO| CONTEXT SWITCHES| CPU| IPC| MEMORY| PAGE FAULTS| SOURCE| SWAPS
ALL:显示所有信息
BLOCK IO:displays counts for block input and output operations
CONTEXT SWITCHES:displays counts for voluntary and involuntary context switches
CPU:displays user and system CPU usage times
IPC:displays counts for messages sent and received
MEMORY:is not currently implemented
PAGE FAULTS:displays counts for major and minor page faults
SOURCE:displays the names of functions from the source code, together with the name and line number of the file in which the function occurs
SWAPS:displays swap counts
实例:
mysql> SELECT @@profiling;
mysql> SET profiling = 1;
mysql> select count(*) from show_table;mysql> show profile;
mysql> show profile all;
mysql> show profile block io;
mysql> show profile context switches;
mysql> show profile cpu;
mysql> show profile ipc;
mysql> show profile memory;
mysql> show profile page faults;
mysql> show profile source;
mysql> show profile swaps;mysql> show profile all for query 1;
mysql> show profile all for query 1 limit 2;
mysql> show profile all for query 1 limit 0,4;
3.32 SHOW PROFILES 语句
作用:同上,参考3.13
基本语法:
SHOW PROFILES
实例:同上,参考3.13
3.33 SHOW RELAYLOG EVENTS 语句
作用:
显示复制从机的relaylog信息
基本语法:
SHOW RELAYLOG EVENTS[IN 'log_name'] [FROM pos] [LIMIT [offset,] row_count]
实例:
show relaylog events;
show relaylog events in 'mysql-relay-bin.000001';
show relaylog events in 'mysql-relay-bin.000001' from 6;
show relaylog events in 'mysql-relay-bin.000001' from 6 limit 3;
show relaylog events in 'mysql-relay-bin.000001' from 6 limit 2,3;
3.34 SHOW SLAVE HOSTS 语句
作用:显示所有在主机注册的从机。
基本语法:
SHOW SLAVE HOSTS
实例:
mysql> SHOW SLAVE HOSTS;
+------------+-----------+------+-----------+
| Server_id | Host | Port | Master_id |
+------------+-----------+------+-----------+
| 192168010 | connect1 | 3306 | 192168011 |
| 1921680101 | connect2 | 3306 | 192168011 |
+------------+-----------+------+-----------+
3.35 SHOW SLAVE STATUS 语句
作用:显示slave从机复制线程的信息。
基本语法:
SHOW SLAVE STATUS
实例:
mysql> SHOW SLAVE STATUS\G
*************************** 1. row ***************************Slave_IO_State: Waiting for master to send eventMaster_Host: localhostMaster_User: rootMaster_Port: 3306Connect_Retry: 3Master_Log_File: gbichot-bin.005Read_Master_Log_Pos: 79Relay_Log_File: gbichot-relay-bin.005Relay_Log_Pos: 548Relay_Master_Log_File: gbichot-bin.005Slave_IO_Running: YesSlave_SQL_Running: YesReplicate_Do_DB:Replicate_Ignore_DB:Replicate_Do_Table:Replicate_Ignore_Table:Replicate_Wild_Do_Table:Replicate_Wild_Ignore_Table:Last_Errno: 0Last_Error:Skip_Counter: 0Exec_Master_Log_Pos: 79Relay_Log_Space: 552Until_Condition: NoneUntil_Log_File:Until_Log_Pos: 0Master_SSL_Allowed: NoMaster_SSL_CA_File:Master_SSL_CA_Path:Master_SSL_Cert:Master_SSL_Cipher:Master_SSL_Key:Seconds_Behind_Master: 8
Master_SSL_Verify_Server_Cert: NoLast_IO_Errno: 0Last_IO_Error:Last_SQL_Errno: 0Last_SQL_Error:Replicate_Ignore_Server_Ids: 0Master_Server_Id: 1
3.36 SHOW STATUS 语句
作用:
SHOW STATUS提供服务器状态信息。此信息也可以使用mysqladmin extended-status命令获得。使用GLOBAL选项,您可以得到所有MySQL连接的状态值。使用SESSION,可以得到所有当前连接的状态值。如果两个选项都不使用,则默认值为SESSION。
基本语法:
SHOW [GLOBAL | SESSION] STATUS[LIKE 'pattern' | WHERE expr]
实例:
mysql> show status;
mysql> show global status;
mysql> show session status;
mysql> show status like 'innodb_buffer%';
mysql> show status where variable_name like 'innodb_buffer%';
+---------------------------------------+-------+
| Variable_name | Value |
+---------------------------------------+-------+
| Innodb_buffer_pool_pages_data | 196 |
| Innodb_buffer_pool_pages_dirty | 0 |
| Innodb_buffer_pool_pages_flushed | 223 |
| Innodb_buffer_pool_pages_free | 7995 |
| Innodb_buffer_pool_pages_misc | 1 |
| Innodb_buffer_pool_pages_total | 8192 |
| Innodb_buffer_pool_read_ahead_rnd | 0 |
| Innodb_buffer_pool_read_ahead | 0 |
| Innodb_buffer_pool_read_ahead_evicted | 0 |
| Innodb_buffer_pool_read_requests | 1839 |
| Innodb_buffer_pool_reads | 145 |
| Innodb_buffer_pool_wait_free | 0 |
| Innodb_buffer_pool_write_requests | 785 |
+---------------------------------------+-------+
3.37 SHOW TABLE STATUS 语句
作用:
SHOW TABLE STATUS的性质与SHOW TABLE类似,不过,可以提供每个表的大量信息。也可以使用mysqlshow --status db_name命令得到此清单。本语句也显示视图信息。
基本语法:
SHOW TABLE STATUS [{FROM | IN} db_name][LIKE 'pattern' | WHERE expr]
实例:
show table status;
show table status from test;
show table status in test;
show table status like 'show_%';
show table status from test like 'show_%';;
show table status from test where engine like 'innodb%';
3.38 SHOW TABLES 语句
作用:
SHOW TABLES列举了给定数据库中的非TEMPORARY表。也可以使用mysqlshow db_name命令得到此清单。本命令也列举数据库中的其它视图。支持FULL修改符,这样SHOW FULL TABLES就可以显示第二个输出列。对于一个表,第二列的值为BASE TABLE;对于一个视图,第二列的值为VIEW。
基本语法:
SHOW [FULL] TABLES [{FROM | IN} db_name][LIKE 'pattern' | WHERE expr]
实例:
mysql> show tables;
mysql> show full tables;
mysql> show tables from test;
mysql> show tables in test;
mysql> show tables like 'show_%';
mysql> show tables from test like 'show_%';
mysql> show full tables from test where table_type like 'base%';
+----------------+------------+
| Tables_in_test | Table_type |
+----------------+------------+
| show_table | BASE TABLE |
| show_table_sec | BASE TABLE |
+----------------+------------+
3.39 SHOW TRIGGERS 语句
作用:
SHOW TRIGGERS列出了目前被MySQL服务器定义的触发程序。
基本语法:
SHOW TRIGGERS [{FROM | IN} db_name][LIKE 'pattern' | WHERE expr]
实例:
mysql> show triggers;
mysql> show triggers from test;
mysql> show triggers in test;
mysql> show triggers like 'show_%';
mysql> show triggers from test like 'show_%';
mysql> show triggers where `trigger` like 'show_%';
mysql> show triggers from test where `table` like 'show_%';
3.40 SHOW VARIABLES 语句
作用:
SHOW VARIABLES显示了部门MySQL系统变量的值。本信息也可以使用mysqladmin variables命令获得。使用GLOBAL选项,您可以获得被用于MySQL新连接的值。使用SESSION,您可以得到对于当前连接起效的值。如果您两个选项都不使用,默认值为SESSION。
基本语法:
SHOW [GLOBAL | SESSION] VARIABLES[LIKE 'pattern' | WHERE expr]
实例:
mysql> show variables;
mysql> show global variables;
mysql> show session variables;
mysql> show variables like 'innodb_f%';
mysql> show variables where variable_name like 'innodb_f%';
+--------------------------------+----------+
| Variable_name | Value |
+--------------------------------+----------+
| innodb_fast_shutdown | 1 |
| innodb_file_format | Antelope |
| innodb_file_format_check | ON |
| innodb_file_format_max | Antelope |
| innodb_file_per_table | OFF |
| innodb_flush_log_at_trx_commit | 1 |
| innodb_flush_method | |
| innodb_force_load_corrupted | OFF |
| innodb_force_recovery | 0 |
+--------------------------------+----------+
3.41 SHOW WARNINGS 语句
作用:
SHOW WARNINGS显示由上一个生成消息的语句导致的错误、警告和注意消息。如果上一个使用表的语句未生成消息,则什么也不显示。SHOW ERRORS是其相关语句,只显示错误。
基本语法:
SHOW WARNINGS [LIMIT [offset,] row_count]
SHOW COUNT(*) WARNINGS
实例:
mysql> show warnings;
mysql> show warnings limit 5;
mysql> show warnings limit 2,5;
mysql> show count(*) warnings;
+-------------------------+
| @@session.warning_count |
+-------------------------+
| 0 |
+-------------------------+
****************************************************************************************
原文地址:http://blog.csdn.net/jesseyoung/article/details/38264887
博客主页:http://blog.csdn.net/jesseyoung
****************************************************************************************
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